[treym]

I am new to this forum and new to welding. Great site with great information.

I have been watching the MIG basics videos from Welding Tips and Tricks. I found the video on setting wire speed and voltage very useful. In particular, I thought that the short circuit MIG wire feed chart and calculations was great. Would this chart and calculations work with FCAW?

From the website and the videos:

"Based on the 1 amp per 1 thousandths of thickness of the metal being welded, there is a number that can be used for all the popular wire diameters that will give you a good starting point for wire speed.

For .045" wire the number is 1

For .035" wire the number is 1.6

for .030" it's 2

.023/.024" the number is 3.5

So the example giving is 1/8" or .125" thick steel.

For .030 wire, 125 x 2 = 250 ipm."

If this does not work for FCAW, is there a chart and calculation similar for flux core?

Thanks,
Trey

[Oscar]

You can find some charts, but unlike solid MIG wire which is pretty consistent from brand-to-brand (in terms of amperage), flux core wire can vary greatly. There is a chart from Lincoln for their 211-MP flux core wire, but it is a bit optimistic IMO for the amperage being delivered at those WFS's, compared to the Blue Demon flux core wire roll that I have.

What diameter flux core wire are you using?

[treym]

Thanks for the response. I will look up the wire specs. I am currently using .35.

[Oscar]

Treym,

For 035 gasless flux core, try 1.8 IPM per amp needed as a starting point.

[tweake]

If this does not work for FCAW, is there a chart and calculation similar for flux core?

Thanks,
Trey

charts are only there to get you into the ball park anyway, so its not a great loss to not have the chart.
the main thing is to adjust it until it runs right.
a beginner mistake is to set the settings them assume the weld is either good or that they are making some kind of mistake.
one of the catches is knowing what a good weld looks like so you know what to adjust to.

some of the flux cores can be really touchy on the settings.

[Oscar]

Just for future reference,

I just checked my 0.030" gasless flux core. With a ½" CTWD,

300 IPM showed ~100A on the MIG ammeter display, so 3 IPM per amp.
397 IPM resulted in ~130A, so that works out to 3.05 IPM per amp

so in pretty good agreement, for this 0.030" flux cored wire. ~ 3 IPM per amp needed.

[treym]

Thanks for everyone's responses. I will try the recommendations as a starting point.

[Oscar]

In this video, he is running 035 gasless flux core at 180 IPM and ended up with 145A at the machine display, but I think the CTWD was a little too close.

4:32 into the video.

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I took a snapshop and used a proportion to determine that, since the wire was 0.035" in real diameter, and on the pic it was 4.5mm, his CTWD ended up being approximately ¼".



I encourage anyone else to do a similar dimensional analysis to see what they come up with for the CTWD. With a ½" CTWD I suspect the amperage would be down in the 105-110A range. So appox 1.5-1.6 IPM per amp.